3QUESTION 3 OF 3
Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
198,000
turns
How to estimate it
Fermi’s official “Napkin math”
It has been turning for about 26 years, and one loop takes about half an hour. How long is it open each day? Call it 10 hours, nearly every day of the year, so 20 turns a day.
- Years since 2000
- ~26
- Days a year
- × 365
- 10 hours × 2 turns
- × 20
- 26 × 365 × 20
- ≈ 190,000
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Turns a year, London Eye figure (ITV, Time Out)
- 7,668
- Mar 2000 to Oct 2026, minus about 10 months shut for Covid
- × 25.8 years
- 7,668 × 25.8
- ≈ 198,000
Reference cited by Fermi: London Eye's 7,668 turns a year (ITV, Time Out) over 25.8 open years since March 2000
How close was your guess?
Your comparison will appear here.
Compare by ratio: divide the larger number by the smaller one. The closer to 1×, the better.